Cleaning pollutants from furnace and incinerator smoke and the like

ABSTRACT

A means for cleaning pollutants from moving gases, such as furnace and incinerator smoke, comprising conducting the gas through a cleaning zone passage of substantial length defined by an encompassing wall from which washing liquid is sprayed to form a dense shower of the washing liquid so that the gas is continuously washed as it progresses through the shower.

United States Patent Katz [ 1 Feb. 8, 1972 [54] CLEANING POLLUTANTS FROMFURNACE AND INCINERATOR SMOKE AND THE LIKE 21 Appl. No.: 29,553

[52] US. Cl. ..55/228, 55/421, 261/118 [51] Int. "I B0ld 47/06 [58]field of Search ..55/220, 227, 228, 260, 84, 55/85, 89, 93, 94, 421;261/115-118, 17

[56] References Cited UNITED STATES PATENTS 917,561 4/1909 Double..261/118 1,050,866 1/1913 Snow ...261/115 1,985,010 12/1934 Berkhul..261/115 2,092,305 9/ 1937 Estes et al ..261/1 16 2,242,294 5/1941 Foxet al ..55/89 2,668,754 2/1954 Lichtenfels .....55/85 3,406,499 10/1968Wiemer .....26l/1 17 3,465,509 9/1969 Gropezaet et al .55/228 3,518,8167/1970 .lalina... ..55/240 1,655,171 l/l928 Wagner .261/116 PrimaryExaminerFrank W. Lutter Assistant Examiner-Bemard Nozick Att0rney-Hill,Sherman, Meroni, Gross & Simpson [57] ABSTRACT A means for cleaningpollutants from moving gases, such as furnace and incinerator smoke,comprising conducting the gas through a cleaning zone passage ofsubstantial length defined by an encompassing wall from which washingliquid is sprayed to form a dense shower of the washing liquid so thatthe gas is continuously washed as it progresses through the shower.

12 Claims, 5 Drawing Figures CLEANING POLLUTANTS FROM FURNACE ANDINCINERATOR SMOKE AND THE LIKE This invention relates to the removal ofpollutants from gas streams, and is more particularly concerned withmeans especially adapted for cleaning air pollutants from furnace andincinerator smoke.

' Numerous and varied schemes have been suggested for smoke abatementwith varying degrees of success. In general, prior arrangements havetended toward complexity involving baffles, bubbling the polluted gasesthrough liquid bath, water curtains, and the like. Various types ofprecipitators are also known. Such disadvantages as complexity of mostprior arrangements or systems, high installation and operating cost andother inherent disadvantages and deficiencies have mitigatedagainsttheir adoption even though proliferation of smoke-emitting unitshas continued with industrial and population expansion.

According to the present invention, the foregoing and otherdisadvantages, inefiiciencies, shortcomings and problems are overcome byproviding a new and improved means for cleaning pollutants from flowinggas streams, and more particularly removing air pollutants from furnaceand incinerator smoke.

An important object of the invention is to provide a new and improvedmeans for cleaning gases and more particularly smoke.

Another object of the invention is to provide a new and improved meansfor efficiently washing pollutants from flowing gas streams such assmoke.

Afurther object of the invention is to provide an improved gas washingsystem adapted for recirculation of the washing fluid.

Still another object of the invention is to provide a new and improvedsimple, economical, efficient and readily adaptable means for cleansinggases and more particularly adapted for cleaning smoke to avoidenvironmental pollution.

Other objects, features and advantages of the invention will be readilyapparent from the following description of certain preferred embodimentsthereof, taken in conjunction with the accompanying drawing, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

FIG. 1 is a schematic illustration of a system embodying features of theinvention;

FIG. 2 is an enlarged sectional elevational view showing the washingunit of the apparatus;

FIG. 3 is an end elevational view taken substantially in the plane ofline III-III of FIG. 2;

FIG. 4 is a sectional detail view taken substantially along the lineIV-IV of FIG. 2; and

FIG. 5 is a fragmentary elevational detail view taken substantially inthe plane of line VV of FIG. 4.

According to the present invention, gas-carried pollutants, such asthose in furnace and incinerator smoke, are cleaned therefrom byconducting the gas with pollutants as a continuously moving streamthrough a cleaning zone passage of substantial length defined by anencompassing wall, and driving spray streams of washing liquid from saidwall in substantially its entire ambit and dispersing the spray streamsto provide a gas permeable dense shower of the washing liquid completelyacross the passage so that the gas stream is thoroughly washed as itprogresses through the shower. The cleaning zone is desirably providedby a device having a perforated tunnel wall surrounded by a water jacketand adapted to be inserted at a suitable convenient point in a flue.

In a typical example of means providing a cleaning zone passage, awashing device 10, is constructed and arranged to be mounted in or aspart of a flue 11 leading from a polluted gas producer such as anincinerator or furnace l2 and exhausting to a receiving space such asatmosphere, for example, through a chimney 13. In order to collectheavier particulate matter from the flue stream, an expansion andcollecting chamber 14 is desirably located to receive thepollutant-laden gases immediately upon entering the flue or soon afterentering the flue. For periodically removing accumulated solids droppingfrom the gas and accumulating in the chamber 14, a cleanout door 15 isdesirably provided for access into the chamber for dumping theaccumulated material therefrom.

In a desirable form the washing device 10 provides a cleaning zonepassage or tunnel of substantial length defined by an encompassing wall17. At its opposite ends the wall 17 is desirably constructed to joinwith respective ends of the pipe providing the flue 11 between which thetunnel unit or device 10 is connected for continuous flow of the gasstream through the tunnel as it flows through the flue. Any suitablemeans may be provided for securing the ends of the tunnel wall to theflue pipe, such as complementary annular flanges 18 on the respectiveopposite ends of the tunnel wall engaging annular collar flanges 19 onthe flue ends and secured thereto as by means of bolts 20. Through thisarrangement, the tunnel wall 17, in effect, becomes a part of the flue.

Means are provided for washing the gas stream as it progresses throughthe tunnel passage by driving spray streams 21 of a washing liquid, suchas water, from substantially the entire area of the tunnel wall 17. Thisis desirably accomplished simply by providing the wall 17 with orificeor nozzle perforations 22 of such size and shape and with their axes sodirected as to emit into the tunnel passage and project the spraystreams 21 in a manner to wash the gas stream quite thoroughly. As shownin FIG. 5, for example, the nozzle orifices 22 are disposed in a uniformpattern in longitudinal and circumferential rows substantiallythroughout the length of the wall and therefore of the tunnel passage.Any other preferred pattern of placement of the orifices 22 may beprovided to afford a spray pattern which will accomplish the desiredresults for the particular gas to be cleaned. By having the orifices 22distributed substantially uniformly throughout substantially the entirearea of the wall 17, extremely thorough washing of the gas stream iseffected as the gas stream progresses through the substantial length ofthe tunnel passage. As best visualized in FIGS. 2 and 4, the spraystreams 21 by their relative density in numbers and projection acrossthe passage throughout substantially the entire length of and from theentire ambit of the wall 17 provide a dense shower of the washing liquidcompletely across the passage. At least some of the spray streams 21collide adjacent the longitudinal center or axis of the tunnel and asplattering occurs which breaks the streams into droplets to which finesolid particles and water soluble chemical constituents of the gasstream adhere and are thus washed from the gas stream as the water dropstoward drain which may be located in the bottom of the tunnel. At leastsome of the spray streams 21 may at least in part due to their velocitycarry over diametrically against the wall 17 from the respectiveorifices 22 from which projected whereby to impinge and wash the wall.Washing effect of the spray streams 21 may be enhanced by having thestreams directed at diagonal angles to the axis of the tunnel, eitherangled in opposition to the direction of movement of the gas stream orin the same direction asthe gas stream is moving, although in part thespray streams may extend generally normal to the axis of the tunnel. Bytheir diagonal disposition, the length of travel of the spray streams isincreased and instead of head-on impingement of the streams they willimpinge and glancingly strike one another and improve the spraydispersion. For example, as shown in FIG. 2, wherein the direction offlow of the gas stream is indicated by the arrow G, the spray streams 21may be directed in part normal to the axis of the tunnel and the gasflow path, and in part diagonally relative to the tunnel axis and biasedin opposition to the direction of flow of the gas stream in a generallycylindrical but preferably at least slightly inwardly flaring section17a of the tunnel wall 17 and which joins a generally elongated bulbarexpansion chamber portion 17b of the wall which increases progressivelyin diameter to a longitudinal mid point of this section and thenprogressively decreases in diameter to substantially the diameter of theflue 11. Within the expansion chamber portion the spray streams 21 mayhave their respective axes generally normal to the portion of the wall17 from which they emanate such that except at the longitudinal centerand maximum diameter of the section 17b the spray streams 21 will be atvarying degrees of diagonal angularity to the gas stream passage axis,being in part directed with a diagonal bias in the direction of movementof the gas stream and in part in opposition to the direction'ofmovement, and at the exit from the tunnel being directly generallynormal to.the axis. It should be understood that although the tunnelwall 17 may be only partially generally cylindrical as shown, it may ifpreferred be substantially cylindrical throughout its length. It mayalso be angular to dip toward a drain-off sump. On the other hand, itmay be constructed substantially as shown in FIG. 2 but with agenerallycylindrical portion at each end and having the bulbar sectionintervening and connecting the generally cylindrical tubular sections.If preferred, of course, the tunnel may merely be bulbar as in thesection 17b. The principal consideration is to provide the mostefficient washing arrangement for any particular installationrequirements. The bulbar arrangement is desirable as providing asubstantial expansion chamber coupled with the dense shower of thewashing liquid environment.

Draining of spent washing liquid is effected in a manner to evacuate thetunnel passage thoroughly and with minimum interference with theshower-producing spray means. By way of example, a drain 23 leads fromthe lowest point in the passage provided by the tunnel, in this instancethe low point in the wallportion 17b, and is of a capacity which assuresrapid drain-off without backup of spent washing liquid along the bottomof the tunnel, so that the orifices 22 will be effective even quiteclose to the drain exit. Although the drain 23 may lead to a sewerdischarge, environmental control is improved by discharging the spentliquid and its load of pollutants into a collecting basin or tank 24which, in a desirable arrangement is a filter or at least contains afilter bed 25. For washing liquid conservation, the clarified and, ifnecessary, chemically treated washing liquid is then recirculatedthrough the washing device 10. This may be effected by way of a duct 27leading from an advantageous portion of the tank 24 such as the bottomand at least from under the filter bed 25, a suitable pump 28 in theduct 27 effecting delivery of the washing liquid under the desiredpressure to the washer. Inasmuch as some of the washing liquid may beevaporated and exhausted with the cleaned flue gases, makeup liquid maybe supplied to the tank 24 through a pipe 29 under the control of avalve 30 which is controlled by means such as a float 31 riding thesurface of the liquid body in the tank 24. Either by way of the makeuppipe 29 or separately, any desirable treating chemicals may be suppliedto the washing liquid in the tank 24. For example, oxides such as mayproduce sulfuric or sulfureous acid in the wash water may beneutralized. by the addition of suitable sweeteners or neutralizers suchas lime. Any suitable means, of which numerous are known in thefiltration art may be employed to clean the filter bed 25 as needed.

In order to distribute the washing liquid delivered to the washingdevice for uniform distribution about the tunnel wall 17, a jacket inthe form of a shell 32 is desirably mounted about the wall 17 in spacedrelation and with the pressure supply duct 27 located to deliver theliquid into the jacket at the most advantageous place such as at asuitable location along its length. At its opposite ends, the jacketshell 32 is hermetically secured to the wall 17 as for example to theattachment flanges 18. Where the drain leaves the tunnel wall 17 andpasses through the jacket shell 32, the shell is hermetically sealedabout the drain.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

1 claim as my invention:

1. Apparatus for cleaning pollutants from moving gas and especiallyadapted for cleaning potential air pollutants from furnace andincinerator smoke, comprising:

means providing a cleaning zone passage having its axis generallyhorizontal and being of substantial length defined by an encompassingwall and through which gas with pollutants is adapted to be conducted asa continuously moving flow;

a spaced jacket about said wall providing a washing liquid supplychamber;

said wall being perforate to provide orifices located at closely spacedpoints in substantially the entire ambit and length of said wall todrive spray streams of washing liquid toward said axis;

said orifices being disposed to direct said streams generally diagonallydownstream in an upstream portion of said passage, generally normal tosaid axis in an intermediate portion of said passage and generallydiagonally upstream in a downstream portion of said passage whereby thespray streams impinge and glancingly strike one another and therebydisperse the spray streams into a gas-permeable dense shower of thewashing liquid completely across and substantially throughout the lengthof the passage to assure thorough washing of the flowing gas as itprogresses along the passage through the shower;

means for supplying the washing liquid to said chamber under pressure todrive the liquid through said orifices to provide said spray streams;

said wall having a low point therein generally centrally along thelength of said passage toward which spent washing liquid is adapted toflow from each end of the passage; and

a drain leading from said low point through said supply chamber and saidjacket and sealed from said supply chamber.

2. Apparatus according to claim 1, in which said orifices in theextremity of said upstream portion of said passage are directedgenerally normal to said axis upstream from said orifices which directthe streams generally diagonally downstream.

3. Apparatus according to claim 1, including orifices upstream from saidorifices which direct the streams generally diagonally downstream, saidupstream orifices being disposed to direct the streams therefromdiagonally generally upstream.

4. Apparatus according to claim 1, including orifices in the downstreamextremity area of said downstream portion of said passage disposed todirect the streams therefrom generally normal to the passage axis.

5. Apparatus according to claim 1, comprising orifices in the upstreamextremity area of said upstream portion of said passage disposed todirect streams therefrom generally normal to said axis, followed byorifices located immediately downstream which are disposed to direct thestreams therefrom generally diagonally upstream relative to said axis,followed by said orifices disposed to direct the streams generallydiagonally downstream.

6. Apparatus according to claim 5, including orifices in the downstreamextremity area of said downstream portion of said passage disposed todirect the streams therefrom generally normal to the passage axis.

7. Apparatus according to claim 1, in which said wall is of generallybulbar form with the narrowest ends adjacent to the ends of saidupstream and downstream portions and with the widest dimension at saidintermediate portion.

8. Apparatus according to claim 7, said wall having a cylindricalportion at the upstream end thereof.

9. Apparatus according to claim 7, said wall having a cylindricalportion at the downstream end thereof.

10. Apparatus according to claim 7, said wall having respectivecylindrical terminal portions at the upstream and downstream endsthereof.

11. Apparatus for cleaning pollutants from moving gas and especiallyadapted for cleaning potential air pollutants from furnace andincinerator smoke, comprising:

means providing a cleaning zone passage having its axis generallyhorizontal and being of substantial length defined by an encompassingwall and through which gas with pollutants is adapted to be conducted asa continuously moving flow;

a spaced jacket about said wall providing a washing liquid supplychamber;

said wall being perforate to provide orifices located at closely spacedpoints in substantially the entire ambit and length of said wall todrive spray streams of washing liquid toward said axis;

said orifices being disposed to direct said streams generally diagonallydownstream in an upstream portion of said passage, generally normal tosaid axis in an intermediate portion of said passage and generallydiagonally upstream in a downstream portion of said passage whereby thespray streams impinge and glancingly strike one another and therebydisperse the spray streams into a gas-permeable dense shower of thewashing liquid completely across and substantially throughout the lengthof the passage to assure thorough washing of the flowing gas as itprogresses along the passage through the shower;

means for supplying the washing liquid to said chamber under pressure todrive the liquid through said orifices to provide said spray streams;

said wall having a low point therein generally centrally along thelength of said passage toward which spent washing liquid is adapted toflow from each end of the passage;

a drain leading from said low point through said supply chamber and saidjacket and sealed from said supply chamber;

said means for supplying the washing liquid including a ductcommunicating with said supply chamber through said jacket spaced fromsaid drain.

12. Apparatus according to claim 11, including means for cleaning andrecirculating the spent washing liquid from said drain through saidduct.

2. Apparatus according to claim 1, in which said orifices in theextremity of said upstream portion of said passage are directedgenerally normal to said axis upstream from said orifices which directthe streams generally diagonally downstream.
 3. Apparatus according toclaim 1, including orifices upstream from said orifices which direct thestreams generally diagonally downstream, said upstream orifices beingdisposed to direct the streams therefrom diagonally generally upstream.4. Apparatus according to claim 1, including orifices in the downstreamextremity area of said downstream portion of said passage disposed todirect The streams therefrom generally normal to the passage axis. 5.Apparatus according to claim 1, comprising orifices in the upstreamextremity area of said upstream portion of said passage disposed todirect streams therefrom generally normal to said axis, followed byorifices located immediately downstream which are disposed to direct thestreams therefrom generally diagonally upstream relative to said axis,followed by said orifices disposed to direct the streams generallydiagonally downstream.
 6. Apparatus according to claim 5, includingorifices in the downstream extremity area of said downstream portion ofsaid passage disposed to direct the streams therefrom generally normalto the passage axis.
 7. Apparatus according to claim 1, in which saidwall is of generally bulbar form with the narrowest ends adjacent to theends of said upstream and downstream portions and with the widestdimension at said intermediate portion.
 8. Apparatus according to claim7, said wall having a cylindrical portion at the upstream end thereof.9. Apparatus according to claim 7, said wall having a cylindricalportion at the downstream end thereof.
 10. Apparatus according to claim7, said wall having respective cylindrical terminal portions at theupstream and downstream ends thereof.
 11. Apparatus for cleaningpollutants from moving gas and especially adapted for cleaning potentialair pollutants from furnace and incinerator smoke, comprising: meansproviding a cleaning zone passage having its axis generally horizontaland being of substantial length defined by an encompassing wall andthrough which gas with pollutants is adapted to be conducted as acontinuously moving flow; a spaced jacket about said wall providing awashing liquid supply chamber; said wall being perforate to provideorifices located at closely spaced points in substantially the entireambit and length of said wall to drive spray streams of washing liquidtoward said axis; said orifices being disposed to direct said streamsgenerally diagonally downstream in an upstream portion of said passage,generally normal to said axis in an intermediate portion of said passageand generally diagonally upstream in a downstream portion of saidpassage whereby the spray streams impinge and glancingly strike oneanother and thereby disperse the spray streams into a gas-permeabledense shower of the washing liquid completely across and substantiallythroughout the length of the passage to assure thorough washing of theflowing gas as it progresses along the passage through the shower; meansfor supplying the washing liquid to said chamber under pressure to drivethe liquid through said orifices to provide said spray streams; saidwall having a low point therein generally centrally along the length ofsaid passage toward which spent washing liquid is adapted to flow fromeach end of the passage; a drain leading from said low point throughsaid supply chamber and said jacket and sealed from said supply chamber;said means for supplying the washing liquid including a ductcommunicating with said supply chamber through said jacket spaced fromsaid drain.
 12. Apparatus according to claim 11, including means forcleaning and recirculating the spent washing liquid from said drainthrough said duct.